1. Field of the Invention
The present invention relates to a screening machine comprising a screen frame which comprises screen cheeks, is made to oscillate by means of a drive and is supported in an elastic manner on a fixed base, and a swing frame which is elastically coupled thereto.
2. Description of the Prior Art
Screening machines with a screening surface made up of screening mats are known from AT 379.088 for example. The movement of the screening mats usually occurs by a amplitude-excited oscillation system which is held on a moved screen frame. The screening mats forming the screening surface are fastened alternatingly on the screen frame and the oscillation system, so that there will be a compression or stretching of the screening mats through the relative movement of the two systems with respect to each other.
In order to obtain several fractions for example it is also known to provide two such amplitude-excited oscillation systems independent from each other in an oscillating screen frame.
This leads to the disadvantage that such a two-deck screening machine is very high with respect to its design and therefore cannot be used everywhere. Moreover, the constructional efforts for two oscillation systems are very high and an adjustment needs to be made for each oscillation system separately. The construction of multi-deck (>2) oscillation systems is therefore out of the question in view of these configurations.